The condition you speak of does exist. I am not sure when it happened but the first example is a 1976 52' and you will notice the distance from spine to edge is equal as you work out to the end. The second example is a 2001 52' and on this one you will notice the distance from spine to edge increases from the tang outward. I measured this at one time but cannot put my fingers on it right now. Also note that at some time Case got rid of the nice crisp acute angle on the coping blade and started rounding it a bit. Not terribly noticeable in these pics but very much so in hand. And depending on what you use a coping blade for this was not an improvement. I have seen both of these conditions on newer than 2001 as well.